Disclosed herein are embodiments of systems, methods, and products comprise a computing device, which allows a device to be used in different classification levels by powering the device down and booting to a different classified level without the need to switch hard drives. The disclosed software shield and persona switcher (Shielder) module provides independent application environments (personas) for separate security domains while allowing fast transition between personas. Shielder module supports multiple security classification via a minimal system storage partitioning. Shielder module allows efficient collection and reallocation of memory and persistent storage according to need and priority. Shielder module provides secure management of communication media by directing the system communication according to the security profile of the active persona.